Trump visits shooting victims amid protests

US President Donald Trump has met victims and first responders from one of last weekend's two deadly mass shootings, while protesters chanting "do something" and "you are why" accused him of inflaming tensions.

Trump visited Miami Valley Hospital in Dayton, Ohio, where the wounded were treated after nine people and the gunman were killed in a rampage early on Sunday.

It was one of two mass shootings 13 hours apart that shocked the country.

Crowds of protesters outside the hospital and in downtown Dayton held signs reading, "hate not welcome here" and "stop this terror" on Wednesday.

Protesters in El Paso with an anti Donald Trump poster ahead of the US president's visit. (AP)A file photo of the shooting at a popular nightlife area of Dayton, Ohio, on the weekend that left nine people dead. (EPA)

White House spokeswoman Stephanie Grisham said on Twitter that Trump stopped by hospital rooms and met with patients while thanking the medical staff for their work.

"You had God watching. I want you to know we're with you all the way," she quoted Trump as saying at the hospital.

Trump also visited the Texas city of El Paso, on the border with Mexico, where 22 people were killed at a Walmart store on Saturday by a 21-year-old man who had posted an anti-immigrant manifesto online.

They told reporters afterward that they urged Trump to call on Senate Republican leader Mitch McConnell to bring the Senate back from its summer recess to work on a bill that expands background checks on gun buyers.

Brown said he asked Trump to promise he would sign that bill.

"He only said that we will get things done," Brown said, adding the president had been "comforting" to the victims.

Whaley said she agreed with Trump's decision not to visit the district where the shooting occurred given the high emotions in the community.

"A lot of people that own businesses in that district are not interested in the president being there," she told reporters.

"A lot of the time his talk can be very divisive and that's the last thing we need in Dayton."

Democrats say Trump's anti-immigrant, racially charged language at rallies and on Twitter has done much to fan racist, white nationalist sentiments, creating a political climate more conducive to hate-based violence.